Antihypertensives

Question 1

Thiazide Diuretics: Agents

Answer 1

• Chlorthalidone
• Hydrochlorothiazide

Question 2

Thiazide diuretics: MOA

Answer 2

decrease Na+ reabsorption in the distal convoluted tubule
- increased excretion of Na, water, K, and Cl
- decreased effectiveness if CrCL < 30

Question 3

Thiazide diuretics: safety / side effects/ monitoring

Answer 3

Contraindications: sulfa alergy

ADE: Electrolyte abnormalities (low K, Cl, MG & high Ca), gout exacerbation, hyperglycemia, hyperlipidemia, photosensitivity, impotance, dizziness, rash, nocturia

Monitor: electrolytes, renal function, fluid status

Question 4

4 preferred initial hypertension treatments

Answer 4

• ACE
• ARB
• NDHP CCB
• Thiazide diuretics

Question 5

CCB MOA

Answer 5

Inhibit Ca+ from entering vascular smooth muscle and cardiac cells -> vasodilation
- Dihydropyridine (DHP) CCB are selective for vasculature
- NDHP are selective for myocardial cells -> weaker heart squeeze & slower heart rate

Question 6

DHP CCB agents

Answer 6

• Amlodipine (Norvasc)
• Nifedipine ER (Procardia XL)
• Nicardipine (Cardine IV)

nicardipine, felodipine, etc

Question 7

DHP CCB safety/side effects/monitoring

Answer 7

Warnings: hypotension (esp in severe aortic stenosis), caution in HF (amlodipine safest)
ADE: edema, HA, flushing, palpitations, reflex tachycardia, gingival hyperplasia
Nifedipine ER -> ghost tablet in stool

Question 8

NDHP CCB agents

Answer 8

• diltiazem (Cardizem, Tiazac)
• verapamil (Verelan)

Question 9

NDHP CCB safety/side effects/monitoring

Answer 9

Contraindications: hypotension, 2nd or 3rd degree heart block
Warnings: HF, bradycardia
ADE: edema, gingival hyperplasia, constipation

Question 10

CCB DDI

Answer 10

All CCBs caution with:
- strong CYP3A4 inhibitors and inducers

NDHP CCB caution with:
- drugs that decrease HR (BB, digoxin, clonidine, amiodarone)
- drugs metabolized by P-gp & CYP3A4 (simvastatin, lovastatin) -> lower statin dose

Question 11

Thiazide diuretic DDI

Answer 11

• Antihypertensives -> hypotension
• drugs that inc sodium & water levels (ex. NSAIDs) -> dec thiazide effectiveness
• Lithium -> dec lithium clearance -> tox
• Dofetilide -> dec dofetilide clearance -> QTpro